Some people simply can't digest milk and products that contain it. The sensitivity to it reduces calcium storage in blood cells. When a bone is made more brittle due to the lack of calcium, the brain can signal for the cells to be repaired, but when the supplements needed aren't there, the signal simply goes away in transit. Trying to find the right treatment for osteoporosis is complicated by the fact that taking huge does of the supplement in pill form sometimes causes other problems, especially in swallowing since it seems to attach itself to the nearest muscle when swallowed. That might seem incomprehensible but to those who suffer from holes in their bones often visible on x ray, the condition known as osteoporosis is very real.
The risk of taking other things in place of milk is sometimes worth taking if one wants to avoid other symptoms of the disorder like a hump back, loss of height (some people dropping more than 2 inches in stature), and a broken bone that might never heal properly. The determination of therapy should be done after an x ray confirms the diagnosis. Once it is made, the mega dosage of whatever the physician recommends should be taken as prescribed and symptoms that might result should be reported who can adjust or change things that are often prescribed for this true and often frightening disorder. The changes caused by the disorder are very physical to the the body and the changes in height and even shoe size causes great distress, obviously, to those afflicted.